It is generally known that a fishing lure with concealed hooks is less likely to become snagged and more attractive to fish. Stationary curved hooks concealed by the fins of minnow-shaped artificial fishing lures are shown in U.S. Pat. No. 3,755,952 to Oliphant and U.S. Pat. No. 1,855,096 to Chamberlaine.
Others have fashioned artificial fishing lures utilizing hooks which are so concealed that they require movement from their concealed position in order to bare the hook. In U.S. Pat. No. 3,159,940 to Bokun, a curved hook is hinged rotatably into a concealed position, springing out when a fish touches the lure. In U.S. Pat. No. 3,631,624 to Edde, a curved hook is ejected longitudinally from a protective chamber by a spring-loaded trigger when a fish strikes the lure. U.S. Pat. Nos. 1,362,562 and 2,814,149 to Doane and Hunicke, respectively, utilize curved hooks whose barbs remain concealed until the fish closes its mouth on the shanks of the hooks, which urges the hooks to rotate about a fixed hinge point and drives the barbs outward into the flesh on the inside of the fish's mouth. In the Doane patent, the hooks are held in the concealed position by the water stream drag on vanes integrally formed on the shanks of the hooks, while in the Hunicke patent this function is performed by a coil spring.